Added ability to configure animation type via IBInspectable property

[ahmedb]

Hi,

For a project I am working on, I was asked to change the animation type. I added an IBInspectable property to allow this. I think it might be useful to others :)

Thanks, Ahmed

[timusus]

@ahmedb thanks for your contribution. Can you resolve the conflicts, so we can have another look?

[ahmedb]

@timusus Just resolved the conflict. Sorry for the delay!